EP1740997B1 - Piezoelectric actuated scanning mirror - Google Patents
Piezoelectric actuated scanning mirror Download PDFInfo
- Publication number
- EP1740997B1 EP1740997B1 EP05737855.6A EP05737855A EP1740997B1 EP 1740997 B1 EP1740997 B1 EP 1740997B1 EP 05737855 A EP05737855 A EP 05737855A EP 1740997 B1 EP1740997 B1 EP 1740997B1
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- EP
- European Patent Office
- Prior art keywords
- mirror
- reflective region
- rotation
- hinge
- offset
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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Classifications
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
- G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
- G02B26/0816—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements
- G02B26/0833—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD
- G02B26/0858—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD the reflecting means being moved or deformed by piezoelectric means
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
- G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
- G02B26/10—Scanning systems
- G02B26/105—Scanning systems with one or more pivoting mirrors or galvano-mirrors
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/12—Picture reproducers
- H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
- H04N9/3141—Constructional details thereof
- H04N9/315—Modulator illumination systems
- H04N9/3161—Modulator illumination systems using laser light sources
Definitions
- This invention relates generally to a laser projection device (LPD), and, more particularly, to an LPD that employs a scanning mirror that may be actuated by a piezoelectric device.
- LPD laser projection device
- one or more mirrors may be used to redirect and/or scan one or more beams of laser light onto a projection surface.
- These mirrors must be capable of rapid, highly-controlled movement in order to accurately position the laser beams on the projection surface.
- any inaccuracy in the positioning of the mirror will result in the laser beams being inaccurately positioned on the projections surface.
- any image projected by the LPD will be distorted.
- the distance between the projection surface and the mirror may be substantial, such that even relatively minor inaccuracies in the positioning of the mirror may produce dramatic mispositioned laser beams on the projection surface.
- U.S. Patent No. 6,198,565 discloses a light deflection element and display apparatus using same.
- U.S. Patent No. 5,208,880 discloses a microdynamical fiber-optic switch and method of switching using same.
- U.S. Patent No. 5,915,063 discloses a variable optical attenuator.
- US 2001/0050801 A1 discloses biased rotatable combdrive devices and methods.
- the present invention is directed to overcoming, or at least reducing, one or more of the problems as set forth above.
- the LPD 100 includes three lasers 102, 104, 106, each capable of emitting a beam of light 108, 110, 112 consisting of a unique color, such as red, green or blue.
- a unique color such as red, green or blue.
- the lasers 102, 104, 106 are arranged in a common plane 114 with the beams of light 108, 110, 112 being angularly directed relatively to one another to fall on a substantially common location 116 on a first scanning device, such as a first scanning mirror 118, from where they are reflected as beams of light 120, 122, 124.
- a first scanning device such as a first scanning mirror 118
- the first scanning mirror 118 oscillates on an axis 120 at a relatively high rate (e.g., 20-30 kHZ). Rotation or oscillation of the first scanning mirror 118 causes the beams of light 108, 110, 112 to be moved.
- the angular position of the first scanning mirror 118 alters, so to does the angle of reflection of the beams of light 120, 122, 124 from the first scanning mirror 118.
- the reflected beams of light 120, 122, 124 are scanned to produce movement of the beams of light 120, 122, 124 along one component of the two-dimensional display.
- the second component of the two-dimensional display is produced by a second scanning device, such as a mirror 126.
- the second mirror 126 is coupled to a motor 128 at a pivot point 130 so as to produce rotational or oscillating movement about an axis that is substantially orthogonal to the axis of rotation of the first mirror 118.
- the beams of light 120, 122, 124 are reflected off of the second mirror 126 as beams of light 132, 134, 136 and directed to a viewing surface 138.
- the viewing surface may take on any of a variety of forms.
- the second mirror oscillates or rotates at a relatively slow rate, as compared to the rate of the first mirror 118 (e.g., 60 hz).
- the beams of light 132, 134, 136 generally follow a path 140 on the display surface 138.
- the path 140 is similar in shape and concept to a raster scan commonly employed in cathode ray tube televisions and computer monitors.
- first and second scanning mirrors 118, 126 While the instant invention is described herein in the context of an embodiment that employs separate first and second scanning mirrors 118, 126, those skilled in the art will appreciate that a similar path 140 may be produced by using a single mirror.
- the single mirror would be capable of being moved about two axis of rotation to provide the fast and slow oscillating movements along two orthogonal axes.
- a controller 142 is provided to controllably energize the lasers 102, 104, 106 to effectively cause the beams of light 120, 122, 124 to be collinear, such that they may be reflected off of the second mirror 126 and delivered to the same point on the viewing surface 138 relatively independent of the distance of the viewing surface 138 from the second mirror 126.
- the beams of light 120, 122 can be made to follow a single, common path (i.e., the beams of light 120, 122 are collinear). For example, if the laser 102 is energized at a first time t1, then the mirror 118 will be at a first position, as represented by the solid lines, and the beam of light 108 will reflect off of the mirror 118 as the beam of light 120.
- the mirror 118 will be at a second position, as represented by the dashed lines, and the beam of light 110 will reflect off of the mirror 118 as the beam of light 122.
- the mirror 118 will be in a position to accurately reflect the beam of light 122 along substantially the same path as the beam of light 120.
- the beams of light 120, 122 are substantially collinear, but are slightly displaced in time. That is, the beams of light 120, 122 will now both be projected onto substantially the same point on the display surface 13 8, but at slightly different times. However, owing to the persistence of the human eye, the variation in timing is not detectable. That is, in the case of the three laser system described in Figure 1 , each of the lasers 102, 104, 106 will controllably deliver laser light of a unique color and intensity to substantially the same point on the viewing surface 132 within a relatively short window of time.
- the human eye will not detect the three separate colors, bur rather will perceive a blending of the three light beams such that a consistent and desired hue appears at that point on the viewing surface. Those skilled in the art will appreciate that this process may be repeated numerous times along the path 140 to recreate a picture on the viewing surface 132.
- the routine begins at block 401 with the controller 142 determining the intensity for each of the lasers. That is, in order for a picture to be properly displayed, the controller 142 is capable of determining the hue of the picture at that small portion of the picture that is about to be projected onto the viewing surface. To reproduce the proper hue, the controller 142 determines the intensity for each of the lasers. This determination may be accomplished in any of a variety of conventional manners, such as via a look-up table, via a mathematical algorithm or the like.
- the controller 142 determines the time at which each of the lasers is to be energized.
- the determination of the timing may be accomplished in any of a variety of conventional manners, such as via a look-up table, via a mathematical algorithm or the like. This technique can be used during a calibration after manufacture. Ordinarily, this timing may be relatively fixed. That is, the timing may be established at the end of the manufacturing process by a factory technician, and thereafter, the controller may simply use these factory determined settings.
- a routine may be established to allow these settings to be altered as needed. That is a software routine may be included to project preselected tuning patterns (such as a cross pattern for each color laser) on the viewing surface. A service technician or consumer may then indicate to the controller (by depressing a preselected sequence of buttons) that the tuning patterns need to be adjusted to cause them to overlap properly. The controller 142 may then use the technician or consumer supplied information to alter the timing of the lasers.
- preselected tuning patterns such as a cross pattern for each color laser
- the controller 142 uses the determined timing and intensity for each of the lasers and controllably energizes the lasers to produce the desired hue at the present location on the viewing surface.
- the control routine 400 is continuously repeated for numerous points along the path 140 to effectively reproduce a picture on the viewing surface.
- a non-resonant scanning mirror 500 is activated using piezoelectric elements 502, 504.
- a characteristic stroke limitation of piezoelectric elements is overcome by applying a force developed by a piezoelectric element at a point very close to the axis of rotation of the mirror 500. Hence, relatively large scan angles can be achieved without relying on high mechanical Q factor.
- the mirror 500 may be formed from a substantially planar sheet of material 500, such as metals, ceramics, semiconductors or the like. Slots or grooves extending substantially through the sheet of material 500 divide the sheet of material 500 into two basic regions, a movable reflective region 502 and a base region 504, which in the illustrated embodiment substantially surrounds the movable reflective region 502.
- the movable reflective region 502 remains coupled to the base region 504 by a pair of split torsion hinges 506.
- the split torsion hinges 506 are formed by slots or grooves that extend substantially through the sheet of material 500 and are substantially aligned with an axis of rotation 508 of the movable reflective surface 502.
- the movable reflective surface 502 is generally free to rotate about the axis 508 so that laser light directed onto the movable reflective surface 502 may be reflected therefrom at various angles.
- Controllable positioning of the movable reflective surface 502 is accomplished by a set of piezoelectric elements 510, 512, 514,516.
- the piezoelectric elements 510, 512, 514, 516 extend between the base region 504 and a foundation, such as a printed circuit (PC) board 518.
- PC printed circuit
- the split hinges 506 provide a restoring force, which aids in returning the movable reflective region 502 to its initial unbiased position.
- Each hinge 506 also acts as a link, transmitting the force from the piezoelectric elements 510, 512, 514, 516 to the mirror 500. Since the forces are applied off-center, they generate torque, which forces the movable reflective region to rotate.
- the embodiment illustrated in Figure 5 is especially efficient when the mirror 500 is constructed using Micro-Electro-Mechanical Systems (MEMS) technology, so the split hinges 506 can be very narrow and the distance between the slots forming the hinges 506 may be very short.
- MEMS Micro-Electro-Mechanical Systems
- FIG. 6A a cross sectional end view of the mirror 500 is illustrated in various modes of operation.
- the piezoelectric elements have been energized in pairs 510, 512: 514,516 to apply forces in the directions indicated by the arrows 600, 602.
- the forces 600, 602 are applied to the base region 504 and are then transmitted to the movable reflective region 502 via the split hinges 506.
- the force applied through the split hinges 506 causes the movable reflective region 502 to rotate in a first direction, as indicated by the arrow 604.
- the amount of rotation may be accurately controlled.
- the amount of force delivered by the piezoelectric elements 510, 512, 514, 516 may be controlled by varying electrical parameters of a signal applied to the piezoelectric elements 510, 512, 514, 516.
- the amount of force generated by the piezoelectric elements 510, 512, 514, 516 may be controlled by varying the voltage, current, frequency, duty cycle, or a combination thereof. Additionally, it may be useful in some applications to apply unequal force through the various piezoelectric elements 510, 512, 514, 516.
- the piezoelectric elements have been energized in pairs 510, 512: 514, 516 in a manner to apply forces in the directions indicated by the arrows 600, 602, which are opposite to the forces shown in Figure 6A . Nevertheless, the forces 600, 602 are applied to the base region 504 and are then transmitted to the movable reflective region 502 via the split hinges 506. The force applied through the split hinges 506 causes the movable reflective region 502 to rotate in a second direction, as indicated by the arrow 604. By controlling the amount of force applied by the piezoelectric elements 510, 512, 514, 516 the amount of rotation may be accurately controlled.
- the amount of force delivered by the piezoelectric elements 510, 512, 514, 516 may be controlled by varying electrical parameters of a signal applied to the piezoelectric elements 510, S 12, 514, 516.
- the amount of force generated by the piezoelectric elements 510, 512, 514, 516 may be controlled by varying the voltage, current, frequency, duty cycle, or a combination thereof. Additionally, it may be useful in some applications to apply unequal force through the various piezoelectric elements 510, 512, 514, 516.
- the degree of rotation may be controlled by first energizing a first pair 510, 512 of the piezoelectric elements for a first range of rotation, and then energizing the second pair 514, 516 oppositely, and at the same time, to produce a second, greater range of rotation. That is, energizing the first pair 510, 512 may be useful to produce rotation in a range of 0-2°, whereas energizing both pairs 510, 512; 514, 516 oppositely and simultaneously may produce rotation in a range of 2-5°.
- varying energization schemes of the piezoelectric elements 510, 512, 514, 516 to produce various desirable rotational movement of the movable reflective region 502 may be employed.
- Figures 7-9 alternative embodiments of the construction of the mirror 500 are shown.
- Figures 7-9 illustrate variations in the formation of the split hinges 506.
- Figures 7A and 7B illustrate a top view and an expanded top view of the mirror 500 having a plurality of hinges with offset, in accordance with the present invention. While the embodiment illustrated in Figure 7 shows two pairs of split hinges on each side of the mirror, those skilled in the art will appreciate that any number of hinge pairs with offset can be used. Further, the offset can have any value, starting from 0 and up to and, possibly, exceeding hinge width ( Fig. 7 shows offset roughly equal to hinge width).
- push-pads 800 which are used to attach the hinges, can be forked to allow some compliance or flexibility in the direction of hinge length and thus compensate for hinge stretching due to its twisting.
- push pads 900, 902 located on both sides of the hinges may be connected by bridges 904 to facilitate mirror handling and mounting. After the mirror is mounted, the bridges 904 may be either removed, or kept if they are sufficiently thin not to create substantial resistance.
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- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Mechanical Optical Scanning Systems (AREA)
- Mechanical Light Control Or Optical Switches (AREA)
- Transforming Electric Information Into Light Information (AREA)
Description
- This invention relates generally to a laser projection device (LPD), and, more particularly, to an LPD that employs a scanning mirror that may be actuated by a piezoelectric device.
- In the field of LPDs, one or more mirrors may be used to redirect and/or scan one or more beams of laser light onto a projection surface. These mirrors must be capable of rapid, highly-controlled movement in order to accurately position the laser beams on the projection surface. As the mirror moves to scan the laser beams, horizontally and/or vertically, any inaccuracy in the positioning of the mirror will result in the laser beams being inaccurately positioned on the projections surface. Thus, any image projected by the LPD will be distorted. In some instances, the distance between the projection surface and the mirror may be substantial, such that even relatively minor inaccuracies in the positioning of the mirror may produce dramatic mispositioned laser beams on the projection surface.
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U.S. Patent No. 6,198,565 discloses a light deflection element and display apparatus using same. -
U.S. Patent No. 5,208,880 discloses a microdynamical fiber-optic switch and method of switching using same. -
U.S. Patent No. 5,915,063 discloses a variable optical attenuator. -
US 2001/0050801 A1 discloses biased rotatable combdrive devices and methods. - The present invention is directed to overcoming, or at least reducing, one or more of the problems as set forth above.
- The present invention is defined by independent claim 1. The dependent claims concern optional features of some embodiments of the invention.
- The invention may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which:
-
Figure 1 is a stylistic block diagram of a top level view of one embodiment of the present invention; -
Figure 2 is a stylistic view of a viewing surface shown inFigure 1 ; -
Figures 3A and 3B depict a top view of a scanning device at various times during its operation; -
Figure 4 depicts one embodiment of a flow chart of a control program that may executed by a controller shown inFigure 1 ; -
Figure 5 depicts a stylistic perspective view of one embodiment of a mirror shown inFigure 1 ; -
Figures 6A and 6B depict an end view of the mirror ofFigure 5 shown in various stages of operation; -
Figures 7A and 7B depict a top view and an enlarged top view of an embodiment of the mirror shown inFigure 1 , in accordance with the present invention; -
Figure 8 depicts a top view of another alternative mirror as shown inFigure 1 with forked push pads; and -
Figure 9 depicts a top view of another alternative mirror as shown inFigure 1 with mounting bridges. - While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.
- Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
- Turning now to the drawings, and specifically referring to
Figure 1 , a stylistic block diagram of a laser projection display (LPD) 100, in accordance with one embodiment of the present invention, is shown. In the illustrated embodiment, theLPD 100 includes threelasers light - The
lasers common plane 114 with the beams oflight common location 116 on a first scanning device, such as afirst scanning mirror 118, from where they are reflected as beams oflight first scanning mirror 118 oscillates on anaxis 120 at a relatively high rate (e.g., 20-30 kHZ). Rotation or oscillation of thefirst scanning mirror 118 causes the beams oflight first scanning mirror 118 alters, so to does the angle of reflection of the beams oflight first scanning mirror 118. Thus, as the mirror oscillates the reflected beams oflight light - The second component of the two-dimensional display is produced by a second scanning device, such as a
mirror 126. In the illustrated embodiment, thesecond mirror 126 is coupled to amotor 128 at apivot point 130 so as to produce rotational or oscillating movement about an axis that is substantially orthogonal to the axis of rotation of thefirst mirror 118. The beams oflight second mirror 126 as beams oflight viewing surface 138. The viewing surface may take on any of a variety of forms. - The second mirror oscillates or rotates at a relatively slow rate, as compared to the rate of the first mirror 118 (e.g., 60 hz). Thus, it will be appreciated that, as shown in
Figure 2 , the beams oflight path 140 on thedisplay surface 138. Those skilled in the art will appreciate that thepath 140 is similar in shape and concept to a raster scan commonly employed in cathode ray tube televisions and computer monitors. - While the instant invention is described herein in the context of an embodiment that employs separate first and
second scanning mirrors similar path 140 may be produced by using a single mirror. The single mirror would be capable of being moved about two axis of rotation to provide the fast and slow oscillating movements along two orthogonal axes. - As is apparent from
Figure 1 , owing to the angular positioning of thelasers lasers light same plane 114 and at the same point (on the rotational axis 120) on the mirror 118), each has a different angle of reflection, which causes the beams oflight controller 142 is provided to controllably energize thelasers light second mirror 126 and delivered to the same point on theviewing surface 138 relatively independent of the distance of theviewing surface 138 from thesecond mirror 126. - Turning now to
Figures 3A and 3B , the operation of thecontroller 142 to cause the beams oflight lasers Figure 3 , but those skilled in the art will appreciate that the concepts discussed herein may be extended to three or more lasers. As shown inFigure 3A , if thelasers light Figure 3B , if thelasers light light laser 102 is energized at a first time t1, then themirror 118 will be at a first position, as represented by the solid lines, and the beam oflight 108 will reflect off of themirror 118 as the beam oflight 120. Subsequently, if thelaser 104 is energized at a second time t2, then themirror 118 will be at a second position, as represented by the dashed lines, and the beam oflight 110 will reflect off of themirror 118 as the beam oflight 122. By precisely controlling the time t2, themirror 118 will be in a position to accurately reflect the beam oflight 122 along substantially the same path as the beam oflight 120. - Thus, through the operation of the
controller 142, the beams oflight light Figure 1 , each of thelasers viewing surface 132 within a relatively short window of time. The human eye will not detect the three separate colors, bur rather will perceive a blending of the three light beams such that a consistent and desired hue appears at that point on the viewing surface. Those skilled in the art will appreciate that this process may be repeated numerous times along thepath 140 to recreate a picture on theviewing surface 132. - Turning now to
Figure 4 , one embodiment of acontrol routine 400 that may be used in thecontroller 142 is illustrated. The routine begins atblock 401 with thecontroller 142 determining the intensity for each of the lasers. That is, in order for a picture to be properly displayed, thecontroller 142 is capable of determining the hue of the picture at that small portion of the picture that is about to be projected onto the viewing surface. To reproduce the proper hue, thecontroller 142 determines the intensity for each of the lasers. This determination may be accomplished in any of a variety of conventional manners, such as via a look-up table, via a mathematical algorithm or the like. - In
block 402, thecontroller 142 determines the time at which each of the lasers is to be energized. The determination of the timing may be accomplished in any of a variety of conventional manners, such as via a look-up table, via a mathematical algorithm or the like. This technique can be used during a calibration after manufacture. Ordinarily, this timing may be relatively fixed. That is, the timing may be established at the end of the manufacturing process by a factory technician, and thereafter, the controller may simply use these factory determined settings. - It may be useful, however, to allow a technician or even a consumer to periodically make adjustments to the timing to account for mechanical changes in the
system 100 that arise from environmental conditions, such as temperature or harsh treatment. Since the timing variations may be accomplished by storing the timing requirements in non-volatile memory, a routine may be established to allow these settings to be altered as needed. That is a software routine may be included to project preselected tuning patterns (such as a cross pattern for each color laser) on the viewing surface. A service technician or consumer may then indicate to the controller (by depressing a preselected sequence of buttons) that the tuning patterns need to be adjusted to cause them to overlap properly. Thecontroller 142 may then use the technician or consumer supplied information to alter the timing of the lasers. - Finally, in
block 403, thecontroller 142 uses the determined timing and intensity for each of the lasers and controllably energizes the lasers to produce the desired hue at the present location on the viewing surface. Thecontrol routine 400 is continuously repeated for numerous points along thepath 140 to effectively reproduce a picture on the viewing surface. - Turning now to
Figure 5 , one embodiment of a mirror that may be employed as the scanning mirrors 118, 126 is shown. In the illustrated embodiment, anon-resonant scanning mirror 500 is activated usingpiezoelectric elements mirror 500. Hence, relatively large scan angles can be achieved without relying on high mechanical Q factor. - The
mirror 500 may be formed from a substantially planar sheet ofmaterial 500, such as metals, ceramics, semiconductors or the like. Slots or grooves extending substantially through the sheet ofmaterial 500 divide the sheet ofmaterial 500 into two basic regions, a movablereflective region 502 and abase region 504, which in the illustrated embodiment substantially surrounds the movablereflective region 502. The movablereflective region 502 remains coupled to thebase region 504 by a pair of split torsion hinges 506. The split torsion hinges 506 are formed by slots or grooves that extend substantially through the sheet ofmaterial 500 and are substantially aligned with an axis ofrotation 508 of the movablereflective surface 502. - The movable
reflective surface 502 is generally free to rotate about theaxis 508 so that laser light directed onto the movablereflective surface 502 may be reflected therefrom at various angles. Controllable positioning of the movablereflective surface 502 is accomplished by a set ofpiezoelectric elements piezoelectric elements base region 504 and a foundation, such as a printed circuit (PC)board 518. Those skilled in the art will appreciate that while the illustrated embodiment of the instant invention utilizes four piezoelectric elements, a smaller or greater number of elements may be employed, depending on the design criteria of the application in which the mirror is being used. - The split hinges 506 provide a restoring force, which aids in returning the movable
reflective region 502 to its initial unbiased position. Eachhinge 506 also acts as a link, transmitting the force from thepiezoelectric elements mirror 500. Since the forces are applied off-center, they generate torque, which forces the movable reflective region to rotate. - The embodiment illustrated in
Figure 5 is especially efficient when themirror 500 is constructed using Micro-Electro-Mechanical Systems (MEMS) technology, so the split hinges 506 can be very narrow and the distance between the slots forming thehinges 506 may be very short. - Turning now to
Figures 6A and 6B , a cross sectional end view of themirror 500 is illustrated in various modes of operation. InFigure 6A , the piezoelectric elements have been energized inpairs 510, 512: 514,516 to apply forces in the directions indicated by thearrows forces base region 504 and are then transmitted to the movablereflective region 502 via the split hinges 506. The force applied through the split hinges 506 causes the movablereflective region 502 to rotate in a first direction, as indicated by thearrow 604. By controlling the amount of force applied by thepiezoelectric elements piezoelectric elements piezoelectric elements piezoelectric elements piezoelectric elements - In
Figure 6B , the piezoelectric elements have been energized inpairs 510, 512: 514, 516 in a manner to apply forces in the directions indicated by thearrows Figure 6A . Nevertheless, theforces base region 504 and are then transmitted to the movablereflective region 502 via the split hinges 506. The force applied through the split hinges 506 causes the movablereflective region 502 to rotate in a second direction, as indicated by thearrow 604. By controlling the amount of force applied by thepiezoelectric elements piezoelectric elements piezoelectric elements 510,S piezoelectric elements piezoelectric elements - Further, in some applications the degree of rotation may be controlled by first energizing a
first pair second pair first pair pairs piezoelectric elements reflective region 502 may be employed. - Turning now to
Figures 7-9 , alternative embodiments of the construction of themirror 500 are shown. In particular,Figures 7-9 illustrate variations in the formation of the split hinges 506.Figures 7A and 7B illustrate a top view and an expanded top view of themirror 500 having a plurality of hinges with offset, in accordance with the present invention. While the embodiment illustrated inFigure 7 shows two pairs of split hinges on each side of the mirror, those skilled in the art will appreciate that any number of hinge pairs with offset can be used. Further, the offset can have any value, starting from 0 and up to and, possibly, exceeding hinge width (Fig. 7 shows offset roughly equal to hinge width). - As shown in
Figure 8 , push-pads 800, which are used to attach the hinges, can be forked to allow some compliance or flexibility in the direction of hinge length and thus compensate for hinge stretching due to its twisting. - Additionally, as shown in
Figure 9 , pushpads bridges 904 to facilitate mirror handling and mounting. After the mirror is mounted, thebridges 904 may be either removed, or kept if they are sufficiently thin not to create substantial resistance.
Claims (4)
- A light scanning apparatus, comprising:a reflective region (502) movable about an axis of rotation (508);a base region (504) coupled to the movable reflective region (502) by a plurality of hinges;a foundation (518); anda plurality of piezoelectric elements (510, 512, 514, 516) extending between the foundation (518) and the base region (502) such that movement of the piezoelectric elements (510, 512, 514, 516) is transferred to the reflective region (502) through the plurality of hinges;characterized in thatsaid plurality of hinges comprises a first hinge pair that extends from the reflective region (502) along the axis of rotation (508) in a first direction and a second hinge pair that extends from the reflective region (502) along the axis of rotation (508) in a second direction opposite the first direction,wherein each of the first hinge pair and the second hinge pair comprises:a first end portion connected to the reflective region (502), a first offset hinge portion, a middle portion traversing the axis of rotation (508), a second offset hinge portion, and a second end portion;wherein the first offset hinge portion extends between the first end portion and the middle portion, and is offset from the axis (508) of rotation in a third direction perpendicular to the first and second directions; andwherein the second offset hinge portion extends between the middle portion and the second end portion, and is offset from the axis (508) of rotation in a fourth direction opposite to the third direction;wherein the base region (504) comprises, for each of the first hinge pair and the second hinge pair:a first extension that extends in the third direction towards the first offset hinge portion and is connected to the middle portion by a first beam running in the first direction and to the first end portion by a second beam running in the second direction; anda second extension that extends in the fourth direction towards the second offset hinge portion and is connected to the second end portion by a third beam running in the first direction and to the middle portion by a fourth beam running in the second direction.
- The light scanning apparatus of claim 1, wherein the reflective region (502) and the base region (504) are formed in a substantially planar sheet of material (500).
- The light scanning apparatus of claim 2, wherein slits or grooves extending substantially through the sheet of material (500) divide the sheet of material (500) into the reflective region (502) and the base region (504).
- The light scanning apparatus of any of claims 1-3, wherein the base region (504) substantially surrounds the reflective region (502).
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/837,037 US7446919B2 (en) | 2004-04-30 | 2004-04-30 | Piezoelectric actuated scanning mirror |
PCT/US2005/013820 WO2005111692A1 (en) | 2004-04-30 | 2005-04-21 | Piezoelectric actuated scanning mirror |
Publications (2)
Publication Number | Publication Date |
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EP1740997A1 EP1740997A1 (en) | 2007-01-10 |
EP1740997B1 true EP1740997B1 (en) | 2014-08-20 |
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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EP05737855.6A Expired - Fee Related EP1740997B1 (en) | 2004-04-30 | 2005-04-21 | Piezoelectric actuated scanning mirror |
Country Status (7)
Country | Link |
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US (1) | US7446919B2 (en) |
EP (1) | EP1740997B1 (en) |
JP (1) | JP4502401B2 (en) |
KR (1) | KR20080036905A (en) |
CN (1) | CN100447612C (en) |
CA (1) | CA2560113A1 (en) |
WO (1) | WO2005111692A1 (en) |
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JP4400608B2 (en) * | 2006-10-19 | 2010-01-20 | セイコーエプソン株式会社 | Actuator, optical scanner, and image forming apparatus |
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US8508098B2 (en) * | 2006-12-03 | 2013-08-13 | Maradin Technologies Ltd. | Gimbaled scanning micro-mirror actuation scheme and architecture |
JP5286906B2 (en) * | 2007-06-08 | 2013-09-11 | 大日本印刷株式会社 | Piezoelectric mirror device, optical apparatus using the same, and method of manufacturing piezoelectric mirror device |
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WO2009147654A1 (en) * | 2008-06-02 | 2009-12-10 | Maradin Technologies Ltd. | Gimbaled scanning micro-mirror apparatus |
JP5539628B2 (en) * | 2008-06-20 | 2014-07-02 | キヤノン電子株式会社 | Micromirror device for optical scanning, optical scanning device, image forming apparatus, display device, and input device |
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TWI408413B (en) | 2011-02-25 | 2013-09-11 | Ind Tech Res Inst | Two dimension scanning and reflecting device |
DE102011006595B4 (en) | 2011-03-31 | 2019-01-17 | Robert Bosch Gmbh | Micromechanical component and production method for a micromechanical component |
WO2013140757A1 (en) * | 2012-03-23 | 2013-09-26 | パナソニック株式会社 | Scanning mirror and scanning image display device |
TWD166688S (en) * | 2014-03-10 | 2015-03-21 | 虹光精密工業股份有限公司 | Scanner |
US9690093B2 (en) * | 2014-10-15 | 2017-06-27 | Medlumics S.L. | Optical beam scanner |
CN105403997A (en) * | 2015-11-19 | 2016-03-16 | 苏州工业园区纳米产业技术研究院有限公司 | Piezoelectric driving two-dimensional scanning micro-mirror |
CN109491078A (en) * | 2019-01-07 | 2019-03-19 | 南京理工大学 | A kind of high-precision micro scanning device |
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US6489934B1 (en) | 2000-07-07 | 2002-12-03 | Judah Klausner | Cellular phone with built in optical projector for display of data |
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AU2002327098A1 (en) * | 2002-08-14 | 2004-03-03 | Fujitsu Limited | Micro rocking device having tosion bar |
JP4898121B2 (en) | 2003-01-08 | 2012-03-14 | エクスプレイ エルティーディー | Image projection device |
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2004
- 2004-04-30 US US10/837,037 patent/US7446919B2/en not_active Expired - Fee Related
-
2005
- 2005-04-21 CN CNB2005800131079A patent/CN100447612C/en not_active Expired - Fee Related
- 2005-04-21 KR KR1020067022714A patent/KR20080036905A/en not_active Application Discontinuation
- 2005-04-21 JP JP2007510828A patent/JP4502401B2/en not_active Expired - Fee Related
- 2005-04-21 CA CA002560113A patent/CA2560113A1/en not_active Abandoned
- 2005-04-21 WO PCT/US2005/013820 patent/WO2005111692A1/en not_active Application Discontinuation
- 2005-04-21 EP EP05737855.6A patent/EP1740997B1/en not_active Expired - Fee Related
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JP2007535706A (en) | 2007-12-06 |
US7446919B2 (en) | 2008-11-04 |
KR20080036905A (en) | 2008-04-29 |
CA2560113A1 (en) | 2005-11-24 |
EP1740997A1 (en) | 2007-01-10 |
JP4502401B2 (en) | 2010-07-14 |
WO2005111692A1 (en) | 2005-11-24 |
CN100447612C (en) | 2008-12-31 |
CN1947051A (en) | 2007-04-11 |
US20050243446A1 (en) | 2005-11-03 |
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